To connect the upper/lower columns of a bunk bed and prevent their detachment due to an earthquake or the like.

This connector consists of a hole 2 provided in a connection part (a) of the upper/lower columns of the bunk bed, a fitting 3 installed in the hole and provided with recesses in respective side faces of the upper part and the lower part, and screws 4 threadedly engaged in the respective upper/lower columns at the recesses of the fitting 3; the upper/lower columns of the bunk bed are connected with the fitting 3 to prevent the lateral deviation and the screws 4 are threadedly engaged in the respective upper/lower columns at the recesses of the fitting 3 to prevent the vertical pull-out of the upper/lower columns and prevent the detachment due to the earthquake or the like.